One guy I liked as a budget option for the Packers' DL in the offseason was Austin Johnson. He was a solid interior DL for the Titans over the course of his rookie deal, signed a one year contract with the Giants in 2020, and then re-upped with them this year on another one year deal.
He's 27 years old, he's played about 56% of the snaps for the Giants this year, and has apparently played pretty well. He has the versatility to spell both Clark and Lowry, which would be really helpful because I don't think Clark's 80+ snap % is sustainable.
His base salary is only 1.5M, which means that if he was a Packer today, he would only count 882K against the cap for the rest of the season.
The Giants seem to be going nowhere fast, and Johnson is a free agent after this season. Furthermore, they've made a huge investment into one iDL (Leonard Williams) and will want to do it again in the next 18 months with another (Dexter Lawrence). If you're going to be that pot committed to two defensive linemen, you're going to want to populate your depth with rookie contracts.
So, for me, Johnson combines a lot of factors that make him a great target: he plays a position of need, he's versatile, he's cheap relative to the cap, he ought to be available, and he shouldn't cost much to acquire in terms of trading assets.